Each deformation of a collector or slipring of rotating electrical machines will lead to problems during operation. These problems manifest themselves in various ways such as brush sparking, high brush wear, noise, damage of brush tops, damage of springs of brush holders and the like. If the slipring is out of round or has any disturbances on the surfaces, the electrical contact between brush and ring is compromised, not only causing the aforementioned problems, but equally causing spark erosion. Because of this erosion the surface of the ring will be attacked even more, causing heavier sparking.
All of the foregoing problems are more pronounced with sliprings and carbon brushes on turbo-alternators. Such turbo-alternators are turbine driven synchronous alternators that are used for power generation in either industry or by power companies, and run at constant speeds of 3000 or 3600 rpm, depending on the required frequency of the alternator output. At 3000 or 3600 rpm the surface speed of the slipring is quiet high with values exceeding 250 km/h or 80 m/sec are not exceptional. The better (the more contact points between the slipring and the brush) the contact between the slipring and the brush, the better the high operational currents is carried from the slipring surface through the carbon brushes, lengthening the brush life.
Regular maintenance of the commutator or slipring is accordingly required. To address surface erosion of the slipring the present invention provides an on-load machining grinding tool.